Gaskets

ABSTRACT

A gasket suitable for use with a gasketed joint assembly having a strip of a sealant material extending from part of an area subjected in use to high loading to another part of that area or to a part of another area subjected to use to high loading.

o l L U rte States atent 1 396539673 Green [4 Apr. 4, 1972 GASKETS 72Inventor: Dermot Green, Cheltenham, England [56] References CM [73]Assignee: Dowty Seals Limited, Ashchurch, Tewkes- UNITED STATES PATENTSy, Gloucestershire. England 2,058,010 10/1936 Fitch ..277/235 8 Nov. 2,l Aukers B App]. No.: 85,979

Foreign Application Priority Data Nov. 19, 1969 Great Britain..56,6l3/69 US. Cl ..277/227, 277/211 Int. Cl ..]Fl6j 15/10 Field ofSearch ..277/209, 211, 207, 227, 235 R,

Primary Examiner-Robert I. Smith Atl0rney-Young & Thompson [57] ABSTRACTA gasket suitable for use with a gasketed joint assembly having a stripof a sealant material extending from part of an area subjected in use tohigh loading to another part of that area or to a part of another areasubjected to use to high loading.

12 Claims, 6 Drawing Figures PATENTEDAPR 4:972 3,653,673

INVENTOR 052/1407 Gags/v TORNEYS GASKETS This invention relates togasketed joint assemblies of the kind comprising two parts which aresecured together with a surface of one part opposed to a surface of theother part. At least one of the parts has therein a fluid-carryingpassageway opening into its said surface. In order to prevent leakage offluid between the opposed surfaces, a gasket is fitted between the twoopposed surfaces. The gasket may or may not have an aperture whichco-operates with the passageway in the one part. Such a gasketed jointassembly is herein referred to as a gasketed joint assembly of the kindstated. In a gasketed joint assembly of the kind stated, the area of thegasket in the region ofa device used to secure the parts together (e.g.,a bolt) is subjected to higher loading than the other areas of thegasket.

The invention also relates to a gasket suitable for use in a gasketedjoint assembly of the kind stated and to methods of making such gaskets.

It is one object of this invention to provide an efficient gasketedjoint assembly and also a gasket suitable for use with such an assembly.

According to this invention a gasket suitable for use with a gasketedjoint assembly of the kind stated comprises in its free state a base ofsubstantially-uniform thickness with a strip of sealant material on asurface thereof extending from one part of an area of the base to besubjected in use to high loading to another part of the said area,whereby the strip and the part of the said area between the ends of thestrip act as an uninterrupted seal for a passageway of a joint part whenassembled between the joint parts.

Also, according to this invention, a gasket suitable for use with agasketed joint assembly of the kind stated comprises in its free state abase of substantially-uniform thickness with strips of sealant materialon a surface thereof, each strip extending from part of an area of thebase to be subjected in use to high loading to a part of an adjacentarea of the base also to be subjected in use to high loading, wherebythe strips and each part of each said area between adjacent ends of twostrips act as an uninterrupted seal for a passageway of ajoint part whenassembled between the joint parts.

The strip of sealant material may gradually change in thickness and/orwidth from each end to a maximum thickness and/r width intermediate theends.

The material of the gasket base and its thickness will be chosen sothat, under the load applied, sufficient compression of the material inthe highly-loaded areas will occur to ensure adequate sealing.Furthermore, the material and thickness are such that little or no flowwill occur in those areas due to the changing mechanical and thermalconditions which arise during use. Thus little or no so-calledtorque-loss will occur and consequently adequate sealing in these partsof the gasket will be maintained in use. Two of the many suitablematerials for the gasket base are paper and asbestos.

At other parts of the gasketed joint where, in use, deflections anddistortions may occur, adequate sealing will be maintained by the stripor strips of sealant material which merge at the ends into thehighly-loaded areas.

Thus a continuous seal is maintained around the passageway although thestrip (or strips) of sealant material is (are) not continuous around thepassageway in a part of the joint.

Each strip of material may conveniently, but not necessarily, bedeposited on the gasket base by a screen-printing process. The surfacetensional effects which arise during such a process provide a depositwhich varies in thickness with respect to width and thus a strip havingthe shape required for the gasket is readily produced.

The strip or strips of material may be deposited on one side only of thebase or on both sides ofthe base.

In some embodiments of the invention, there will be a passageway in onlyone of the parts, and the gasket may or may not have a correspondingaperture.

In other embodiments of the invention, there will be a passageway in onepart which is to be joined to a passageway in the other part. The gasketwill then have an aperture which allows fluid to flow from thepassageway in one part to the passageway in the other part. Such agasket may have a pair of holes adjacent the periphery of the aperturethrough which devices, e.g., bolts, may be passed to secure the twoparts together. Such a gasket will have two strips of sealant materialabout the aperture, the ends being separated by the area of the gasketbase in the region of the holes.

In further embodiments of the invention, each part will have severalpassageways and the other part will have co-operating passageways. Thegasket will then have several apertures and some at least of theapertures may have an adjacent hole through which a securing device maypass. An aperture so associated with a hole will have a single strip ofmaterial thereabout, extending from one position near to the hole toanother position near to the hole.

Several gaskets in accordance with the invention will now be describedby way of example with reference to the accompanying drawings.

In the drawings:

FIG. 1 is an elevational view of a gasketed joint assembly,

FIG. 2 is a plan view of a gasket suitable for use with the joint ofFIG. 1,

FIG. 3 is a sectional view, on an enlarged scale, taken along the lineIII III of FIG. 2,

FIG. 4 is a sectional view, on an enlarged scale, taken along the lineIV IV ofFIG. 2,

FIG. 5 is a plan view of a gasket suitable for use with another gasketjoint assembly, and

FIG. 6 is a plan view of a gasket suitable for use with yet anothergasket joint assembly.

Referring to FIGS. 1 to 4 of the accompanying drawings, the gasketedjoint assembly includes two parts 1 and 2 which are joined together bytwo bolts 3 and 4 (which are threaded into part 2) and are separated bya gasket 5. Each part, 1 and 2, has aligned fluid-carrying passageways 6and 7.

The gasket 5 comprises a base 8 of substantially constant thickness. Thebase has an aperture 9 which, when the gasket is assembled in the joint,will be aligned with the two passageways 6 and 7. The base also has twobolt holes 10 and 11 which, when the gasket is assembled in the joint,will be aligned with the bolts 3 and 4.

Two strips 12 and 13 of sealant material are deposited by ascreen-printing process onto one of the surfaces of the base. The strip12 emerges from the area of the base adjacent the bolt hole 10, followsthe periphery of the aperture 9 and merges into the area adjacent thebolt hole 11. The strip 13 emerges from another part of the areaadjacent the bolt hole 11, follows the periphery of the aperture 9 andmerges into another part of the area adjacent the bolt hole 10.

Two further strips 14 and 15 of sealant material are deposited by ascreen-printing process onto the other of the surfaces of the base,their dispositions and shapes being the same as those of the stripsshown in FIG. 2.

The areas from which the strips emerge and into which they merge areareas which, in the assembled gasketed joint, are subjected to highloading by reason of the bolted connections. The areas between theadjacent ends of the strips are also subjected to high loading whenassembled and the two strips and the parts of the areas between adjacentends of the strips act as an uninterrupted seal for the passageways 6and 7.

Furthermore in this embodiment, each strip gradually changes inthickness (see FIG. 4) from each end, being at a maximum about half waybetween its ends. Thus the parts are capable of the small deflectionswhich occur in use in the areas remote from the bolts, and the varyingstrip thickness accommodates these deflections.

The gasket shown in FIG. 5 is suitable for use in a gasketed joint whereonly one of the parts has a passageway. Such a gasket and the associatedpart which does not have a passageway thus act to blank-off the end ofthe passageway in the other part. This gasket, except for the fact thatit lacks an aperture, is the same as that shown in FIG. 2 and comprisesa base 21, bolt holes 22 and 23 and strips of sealant material 24 and25. The undersurface of the gasket has further strips which correspondto those shown in FIG. 5.

The gasket shown in FIG. 6 is suitable for use in a gasketed joint whereeach part has four fluid-carrying passageways.

The gasket comprises a base 31, four bolt holes 32, 33, 34 and 35, fourapertures 36, 37, 38 and 39 and four strips ofsealant material 40, 41,42 and 43 which are deposited thereon by, say, a screen-printingprocess.

Each strip, as is readily seen in the FIG. 6, emerges from one part ofan area adjacent a bolt hole which, when assembled in a gasketed joint,is subjected to high loading, extends for an appreciable distance aboutthe periphery of the aperture adjacent that hole, and finally mergesinto another part of the area from which it emerges.

The undersurface of the base 31 also has four strips of sealant materialwhich correspond to the strips 40, 41, 42 and 43. Each strip and thepart of the area between the ends of the strip act as an uninterruptedseal when the gasket is assembled in a joint. Thus each of the fourpassageways is sealed against leakage from a passage.

Many materials may be employed for the sealant strip or strips and, whena screen-printing process is used for deposition thereof on the base ofa gasket, the materials will be in a condition suitable forscreen-printing. Examples of such materials are epoxy-resincompositions, urethanes and silicones.

Although in the embodiments described above, each surface of the basehas strips, in other embodiments the strips are only provided on oneofits surfaces.

1 claim as my invention:

1. A gasket, suitable for use with a gasketed joint assembly of the kindstated, comprising in its free state a base of substantially-uniformthickness with a strip of sealant material on a surface thereofextending from one part of an area of the base to be subjected in use tohigh loading to another part of the said area, whereby the strip and thepart of the said area between the ends of the strip act as anuninterrupted seal for a passageway of a joint part when assembledbetween the joint parts.

2. A gasket as claimed in claim 1 wherein a strip changes in thicknessfrom each end thereof, having a maximum thickness intermediate its ends.

3. A gasket as claimed in claim 1 wherein a strip changes in width fromeach end thereof, having a maximum width intermediate its ends.

4. A gasket as claimed in claim 1 wherein a strip changes in thicknessand in width from each end thereof, having a maximum thickness and amaximum width intermediate its ends.

5. A gasket as claimed in claim 1 in which the strip is screenprinted onthe base.

6. A gasketed joint assembly of the kind stated having a gasket asclaimed in claim 1.

7. A gasket, suitable for use with a gasketed joint assembly of the kindstated, comprising in its free state a base of substantially-uniformthickness with strips of sealant material on a surface thereof, eachstrip extending from part of an area of the base to be subjected in useto high loading to a part of an adjacent-area of the base also to besubjected in use to high loading, whereby the strips and each part ofeach said area between adjacent ends of two strips act as anuninterrupted seal for a passageway of a joint part when assembledbetween the joint parts.

8. A gasket as claimed in claim 7 wherein a strip changes in thicknessfrom each end thereof, having a maximum thickness intermediate its ends.

9. As gasket as claimed in claim 7 wherein a strip changes in width fromeach end thereof, having a maximum width intermediate its ends.

10. A gasket as claimed in claim 7 wherein a strip changes in thicknessand in width from each end thereof, having a maximum thickness and amaximum width intermediate its ends.

11. A gasket as claimed in claim 7 in which the strips arescreen-printed on the base.

12. A gasketed joint assembly of the kind stated having a gasket asclaimed in claim 7.

1. A gasket, suitable for use with a gasketed joint assembly of the kindstated, comprising in its free state a base of substantially-uniformthickness with a strip of sealant material on a surface thereofextending from one part of an area of the base to be subjected in use tohigh loading to another part of the said area, whereby the strip and thepart of the said area between the ends of the strip act as anuninterrupted seal for a passageway of a joint part when assembledbetween the joint parts.
 2. A gasket as claimed in claim 1 wherein astrip changes in thickness from each end thereof, having a maximumthickness intermediate its ends.
 3. A gasket as claimed in claim 1wherein a strip changes in width from each end thereof, having a maximumwidth intermediate its ends.
 4. A gasket as claimed in claim 1 wherein astrip changes in thickness and in width from each end thereof, having amaximum thickness and a maximum width intermediate its ends.
 5. A gasketas claimed in claim 1 in which the strip is screen-printed on the base.6. A gasketed joint assembly of the kind stated having a gasket asclaimed in claim
 1. 7. A gasket, suitable for use with a gasketed jointassembly of the kind stated, comprising in its free state a base ofsubstantially-uniform thickness with strips of sealant material on asurface thereof, each strip extending from part of an area of the baseto be subjected in use to high loading to a part of an adjacent area ofthe base also to be subjected in use to high loading, whereby the stripsand each part of each said area between adjacent ends of two strips actas an uninterrupted seal for a passageway of a joint part when assembledbetween the joint parts.
 8. A gasket as claimed in claim 7 wherein astrip changes in thickness from each end thereof, having a maximumthickness intermediate its ends.
 9. As gasket as claimed in claim 7wherein a strip changes in width from each end thereof, having a maximumwidth intermediate its ends.
 10. A gasket as claimed in claim 7 whereina strip changes in thickness and in width from each end thereof, havinga maximum thickness and a maximum width intermediate its ends.
 11. Agasket as claimed in claim 7 in which the strips are screen-printed onthe base.
 12. A gasketed joint assembly of the kind stated having agasket as claimed in claim 7.